Improvement in ovens or tunnels for drying brick



UNITED STATES PATENT QFFIGE.

JOHN K. CALDWELL, OF PHILADELPHIA, PENNSYLVANIA.

IMPROVEMENT IN OVENS OR TUNNELS FOR DRYING BRICK, 84.0.

Specification forming part of Letters Patent No. 198,347, dated December18, 1877; application filed 7 November 1, 1877.

To all whom it may concern: 7

Be it known that I, JOHN K. CALDWELL, of Philadelphia, in the county ofPhiladelphia and State of Pennsylvania, have invented certain new anduseful Improvements in Ovens or Tunnels for Drying Bricks and otherArticles; and I do hereby declare the following to be a full, clear, andexact description of the invention, such as will enable others skilledin the art to which it pertains to make and use it, reference being'hadto the accompanying drawings, which form part of this specification, inwhich- Figure 1 is a vertical longitudinal section, and Fig. 2 is ahorizontal section, of my improved oven or tunnel.

My invention has for its primary object the utilization, to a morecomplete extent than has been heretofore attained, of the heat employedfor drying bricks and other articles in tunnels or ovens.

My improvements consist, primarily, in introducing the products ofcombustion from the radiating-pipes into the drying-chamber at or towardthe rear part of said chamber, and, in combination therewith, theenlargement of said rear part, so as to avoid the collection of moisturein condensed form in injurious proximity to the bricks or other articlesbeing Referring to the accompanying drawing, A represents a tunnel oroven for drying bricks and other articles, and B B the side wallsthereof, having ledges or tracks 12 b for the cars. 0 O are pipes, whichcarry off the products of combustion from a furnace, D. Heretofore saidpipes have been arranged simply for radiating purposes, carrying theircontents to a smoke-stack, E, or cross-flue E. This entails aconsiderable waste, as it is found that all the heat of said products ofcombustion will not be given off by radiation. To avoid such waste Icause the radiating-pipes G C to terminate in open ends 0 0,respectively, before reaching the end wall L of the oven, or thecross-flue E, which allows their contents to escape and ascend into thedrying-chamber. The heat of said contents is thus completely utilized,carrying of the moisture from the rear end of the tunnel, or end wherethe cars enter, through the draft-flue, and assisting the draft orair-current in said tunnel.

K is the roof or ceiling of the tunnel, which is horizontal and parallelwith the tracks or ledges b b for a considerable distance from the frontor furnace end. At a point, K, said ceiling begins to ascend in stepshaving horizontal treads k and inclined faces 70', said steps continuinguntil the draft-flue F is reached. This elevation of the ceiling givesan increased area at that end of the tunnel Where the cars enter for thedistribution of the moisture arisin g from the articles being dried, andalso affords space for the passage of the air-currents above saidarticles without interruption of the draft when the rear door (indicatedat g) is opened for the admission of the cars, or for other purposes.This enlarged area of the tunnel may be also obtained by flaring thewalls B B, as shown in Fig. 2; and instead of causing the pipes C O toterminate in open ends, they may have apertures in their walls or otherorifices for the escape of their contents, said escapeopenings beinggraduated so as to increase the volume emitted as the rear end of thetunnel is approached. Where two pipes having open ends, as shown in thedrawing, are used, they should be of unequal length, so as to avoid thedischarge of the contents of both at the same point.

The operation is substantially as follows: The cars (one of which isindicated in the drawing by the letter I, its load being represented atM) enter the tunnel at the rear end G through a door, 9, and proceedgradually toward the furnace end H, where they make their exit through adoor, h. The products of combustion pass from the furnace D rearwardlythrough the pipes O C, the latter radiating heat upon the articles onthe cars above. Before the end of the tunnel is reached the products ofcombustion are allowed to escape from the smoke-pipes and ascend intothe drying-chamber above. An air-current, induced by a blower or othermeans from the front to the rear of the tunnel, assists in the drying,and carries off the moisture eliminated from the bricks, as well as theproducts of combustion, to the draft-flue. By this means the articles tobe dried will be first brought into contact with the products ofcombustion, which take up and carry ofl', in conjunction with theair-current which they assist, the moisture eliminated, said articlesbeing then brought within the influence of the radiated heat given ofl'from the pipes O C in the more forward part of the tunnel.

Where pressed bricks or other articles likely to be injuriouslyali'ected by direct contact with the products of combustion are to bedried, the smoke-pipes O 0 should be continued unopened to the chimney Eor crossflue E, leading to the latter.

What I claim as my invention is 1. A drying tunnel or oven for brick,having a smoke pipe or pipes terminating therein, and arranged todischarge the products of combustion into the dryingchamber near itsmouth or entrance, substantially as shown and described.

2. A tunnel or oven for drying bricks or other articles, havingsmoke-pipes arranged to carry their contents a certain distance, andthen discharge said contents to permit their admission to thedrying-chamber, so that the articles being dried will first come incontact with the products of combustion from the furnace, and then besubjected to radiated heat, substantially as set forth.

3. The method herein described of drying bricks and other articles bydirect contact with the products of combustion first, and by radiatedheat afterward, substantially as set forth.

4. The smoke-pipes G and O, of unequal length, arranged within thetunnelor oven A, to radiate heat and discharge their contents therein,substantially as shown and described.

5. The combination, with the tunnel A, hav in g its rear end enlarged,as set forth, of the smoke-pipes C 0 arranged to discharge theircontents into said tunnel, as shown.

In testimony that I claim the foregoing I have hereunto set my hand this31st day of October, 1877.

JOHN K. CALDWELL.

Witnesses M. D. CONNOLLY, CHAS. F. VAN HORN.

